Chinese populations along the Yangtze River are expected to suffer severe floods as heavy rains threaten barriers and control efforts.
Chen Guiya, deputy director of the Yangtze River Water Resources Committee, warned that the situation was critical with several damaged riverbanks and heavy rain.
"Flood control facilities, especially main dikes, along the Yangtze River have been reinforced since 1998 to stand severe floods, but rising water levels have damaged many riverbanks in the middle and lower reaches of Yangtze, posing great danger," state-run media quoted Chen as saying.
The national meteorological authority renewed its high alert for heavy rain in the southern and south-western regions for this week, Xinhua news agency said.
The Yangtze River saw its first flood peak on Friday. The Three Gorges Dam increased water discharge to allow the peak to pass through.
The death toll rose to 23 Sunday from a mudslide in southwestern Guizhou province.
Heavy rains were also battering the provinces of Hubei, Anhui, Jiangsu, Hunan, Jiangxi and the Guangxi Zhuang Autonomous Region.
Thousands of soldiers, firemen and relief workers are working around the clock to shore up flood control.
Troops in Hubei used a ton of explosives to open a sluice channel for an overflowing reservoir near several key railway and highway lines on Saturday.
A dam breach of the reservoir could put about 70,000 lives in danger, Xinhua quoted local officials saying.